Analysis of NASA meteorite landings data

Meteorite analysis

library(dplyr)
library(readr)
library(leaflet)
library(ggplot2)
library(knitr)

Import data

meteorites <- read_csv(
  "Meteorite_Landings.csv", 
  col_types = cols(year = col_character())
) %>% 
  rename (mass = `mass (g)` ) %>% 
  mutate( 
    date =  as.POSIXct(year,format="%d/%m/%Y %H:%M:%OS"), 
    recency = 2020 - lubridate::year(date)
  )

kable(head(meteorites, 7))

name	id	nametype	recclass	mass	fall	year	reclat	reclong	GeoLocation	date	recency
Aachen	1	Valid	L5	21	Fell	01/01/1880 12:00:00 AM	50.77500	6.08333	(50.775, 6.08333)	1880-01-01 12:00:00	140
Aarhus	2	Valid	H6	720	Fell	01/01/1951 12:00:00 AM	56.18333	10.23333	(56.18333, 10.23333)	1951-01-01 12:00:00	69
Abee	6	Valid	EH4	107000	Fell	01/01/1952 12:00:00 AM	54.21667	-113.00000	(54.21667, -113.0)	1952-01-01 12:00:00	68
Acapulco	10	Valid	Acapulcoite	1914	Fell	01/01/1976 12:00:00 AM	16.88333	-99.90000	(16.88333, -99.9)	1976-01-01 12:00:00	44
Achiras	370	Valid	L6	780	Fell	01/01/1902 12:00:00 AM	-33.16667	-64.95000	(-33.16667, -64.95)	1902-01-01 12:00:00	118
Adhi Kot	379	Valid	EH4	4239	Fell	01/01/1919 12:00:00 AM	32.10000	71.80000	(32.1, 71.8)	1919-01-01 12:00:00	101
Adzhi-Bogdo (stone)	390	Valid	LL3-6	910	Fell	01/01/1949 12:00:00 AM	44.83333	95.16667	(44.83333, 95.16667)	1949-01-01 12:00:00	71

data exploration

logg mass

meteorites = meteorites %>% 
  filter( recency >= 0) %>% 
  mutate(
    log_mass = log10(mass)
  )
ggplot(meteorites, aes(x=log_mass)) + geom_histogram(col = "black")

Recency in years

meteorites = meteorites %>% 
  filter( recency >= 0, recency < 200)

ggplot(meteorites, aes(x=recency)) + geom_histogram(col = "black", binwidth = 5)

Meteorite class

meteorites %>% 
  group_by(recclass) %>%
  summarise(n=n()) %>%
  arrange(desc(n)) %>% 
  head(25) %>% 
  ggplot(aes(recclass, weight = n)) +
  geom_bar()

time series

meteorites %>% ggplot(aes(x = date, y = mass)) + geom_line()

leaflet map

Interactive map of astroid locations

reds <- colorNumeric("Reds", domain = NULL)

labels = paste(sep = "<br>", meteorites$name, lubridate::year(meteorites$date))
leaflet(
  data = meteorites, 
  width = "1400px", height = "1100px",
  ) %>% 
  addTiles() %>%
  setView(5,50, zoom = 5) %>% 
  addCircleMarkers(
    ~reclong, ~reclat,
    label = ~labels, 
    radius = ~0.8*log_mass,stroke = TRUE, weight = 2,
    fillOpacity = .75,
    color = ~reds(recency)
  ) %>% 
  addLegend(
    pal = reds,
    values = ~recency, 
    group = "circles", position = "bottomleft", title = "recency (in years)"
  ) 

## Warning in validateCoords(lng, lat, funcName): Data contains 7201 rows with either missing or invalid lat/lon values and will be ignored